1. Field of the Invention
This invention relates to a structure of mounting electronic control units, used, for example, in a vehicle, on a junction block.
2. Description of the Related Art
Usually, only one electronic control unit was mounted on a junction block (electric connection box), and when a power source and a ground wire, a switch signal wire, a motor signal wire or the like, which were required for the electronic control unit, were wired within the junction block, these were mounted in an integrated manner.
FIG. 14 is an exploded perspective view of one conventional electronic control unit mounting structure, and FIG. 15 is a cross-sectional view of the electronic control unit mounting structure in its assembled condition.
A junction block includes wiring members, such as a stacked bus bar 3, mounted between an upper casing 2 and a lower casing 1. A printed circuit board 4 of the electronic control unit, having a plurality of electronic parts 42 (FIG. 15) mounted thereon, is mounted above the stacked bus bar, and further a case portion 5 is mounted on the printed circuit board 4.
Upstanding male terminals (tab terminals) 31, serving as connection terminals for transmitting signals necessary for the electronic control unit, are provided for connecting the printed circuit board 4 of the electronic control unit to the stacked bus bar 3 of the junction block. These male terminals extend through the printed circuit board 4 of the electronic control unit, and are inserted into a connector 41, mounted on the obverse surface of this printed circuit board, so that the printed circuit board 4 of the electronic control unit is electrically connected to the stacked bus bar 3 of the junction block.
Although a plurality of electronic control units were mounted on a vehicle, one electronic control unit was usually mounted on a junction block, and therefore it was necessary to mount the other electric control units separately from the junction block.
However, when the other electronic control units, which can not be mounted on the junction block, are mounted separately from this junction block, there is needed wire harnesses for connecting these separate electronic control units to the junction block, and therefore the weight of the vehicle increases, and also the cost increases.
And besides, there are optional vehicle electronic control units which are mounted in accordance with the grade and the specification, and for mounting these optional units, it was necessary to prepare wire harnesses for these optional units.
This invention has been made in order to solve the above problems of the prior art, and an object of the invention is to provide an electronic control unit mounting structure in which even when a plurality of electronic control units are to be mounted, it is not necessary to use wire harnesses for connecting these electronic control units to a junction block, thereby reducing the weight of a vehicle and the cost.
To achieve the above object, according to the present invention, there is provided a electronic control unit mounting structure wherein electronic control units are mounted on a junction block; characterized in that the plurality of electronic control units, each having a connector of a through construction mounted thereon, are superposed in such a posture that the connectors are disposed in registry with each other in an upward-downward direction, and connection terminals of the junction block are inserted in the connectors.
In this construction, the plurality of electronic control units, each having the connector of the through construction mounted thereon, are superposed in such a posture that the connectors are disposed in registry with each other in the upward-downward direction, and in this condition the connection terminals of the junction block are inserted in the connectors. Therefore, even when the plurality of electronic control units are mounted, there is no need to provide a wire harness for connecting each electronic control unit to the junction block since the electronic control units are integrated with the junction block.
In one aspect of the invention, obverse surfaces of the electronic control units face in the same direction. With this arrangement, even when the plurality of electronic control units are mounted, each electronic control unit does not need to be changed in posture, and therefore the assemblage is simplified.
In another aspect of the invention, the directions of obverse surfaces of the adjacent electronic control units are reverse to each other. With this arrangement, even when the plurality of electronic control units are mounted, the length of the terminals of the junction block is reduced since the connectors of the adjacent electronic control units face each other, and therefore the production of the terminals is simplified.
In the invention, preferably, spacers are interposed between the adjacent electronic control units. With this construction, the electronic control units can be easily kept in the predetermined posture, and therefore the assemblage is simplified.
In the invention, at least one of the electronic control units is selected from a plurality of prepared electronic control units. In this case, the optional specification can be easily met with.